Draft control



Oct. 3, 1944.

J. L. COBURN ET AL DRAFT CONTROL Filed Jan. 27, 1941 IJZJHNLUCOBURN2/ 7777i Patented Oct. 3, 1944 DRAFT CONTROL John L. Coburn and Matthew R. Coburn, Des Moines, Iowa Application January 27, 1941, Serial No. 376,147

4 Claims.

This invention relates to draft controls; it is most particularly, but not exclusively, concerned with means for controlling drafts on gas and oil burners.

Certain problems in connection with the control of drafts have heretofore gone unsolved, and it is our purpose to aid in increasing the practicability of heaters, and especially oil and gas heaters. Substantial difliculty has been experienced in conjunction with down drafts extinguishing the pilot flames of gas burners, an occurrence which is obviously most undesirable. In the draft controls heretofore available, it has been possible for the draft to travel either way, depending upon which direction it is strongest; a strong downward draft coming into contact with the tiny pilot flam frequently operates to extinguish the flame and leave the poisonous gas pouring into the room. Another objectionable feature has been the fact that the down drafts, when they occur, have a tendency to fill the heating chamber with cold air from out of doors and hence to cool the object being heated and to decrease generally the efliciency of the device.

It is an object of this invention to provide a draft control which will substantially eliminate the presence of down drafts in the combustion chamber of heating units.

Another object of this invention is to divert drafts coming downwardly through the chimney out into the basement or other room in which the heating unit happen to be situated. Yet another object of this invention is to provide a draft control unit in which th fumes from the combustion chamber are directed by baflle plates indirectly into the chimney flue and in which the drafts coming down the chimney are diverted by bafile plates from the heating unit flue.

Still another object of this invention is to provide a draft control in which the heater flue is out of alignment with the chimney flue.

Other objects of this invention will become apparent to those skilled in the art as we proceed with the disclosure.

For the purposes of this specification, "primary chamber, unless otherwise specified, will be intended to designate that chamber of our novel draft control into which the heater flue enters; and secondary chamber will be intended to signify the chamber which connects directly into the chimney flue.

In order that a clear and concise conception of our invention may be had, reference should be had to the accompanying drawing, forming a part of this specification, in which:

Fig, 1 is a side elevational view of the preferred form of our invention, including fragmentary connections.

Fig. 2 is a bottom view of Fig. 1.

Fig. 3 is a vertical cross section of Fig. 2 taken on line 3-3 thereof.

Referring to the drawing, reference number Ill refers to the main housing which is fragmentarily divided into two compartments by the partition II. The chimney flue outlet, which is .a suitable opening in the Wall I2 of the housing I0, is. designated by the reference character I3. A stub pipe communicates with the chimney flue and is shown at I4. The heater flue enters our draft control device through the opening I5, in which is shown a stub pipe I6. The partition II is provided with one or more openings I! through which the primary chamber I8 is in communication with the secondary chamber I9. Louvers 20 are preferably provided on the partition II extending into the secondary chamber l9 and inclined away from the chimney flue intake I3. Except for the openings heretofore described, namely the heater flue entrance I5 and the openings IT in the partition II, the primary chamber is closed. The secondary chamber on the other hand is preferably entirely open at its end 2|, which is opposite the chimney flue intake I3.

Under normal operating conditions, the gases from the heating unit enter our control unit through the opening I5. Being otherwise confined, they take the path shown by the arrows out through the openings I! and into the secondary chamber I9; the inclined louvers 20 cause the gases to take a downwardly inclined course until they have passed said louvers, whereupon they are drawn by th normal draft conditions upwardly and out through the opening I3. In the event that draft conditions are abnormal, and a downward draft exists, a circumstance which is most likely tooccur when the heatin unit is not in operation, it will be directed out into the room through the opening 2| rather than into the primary chamber I 8 and thence through the heater flue entrance opening I5 into the combustion chamber where it might extinguish the pilot light,

and would, in any event, tend to cool the comgalvanized sheet metal; it may, of course, also be a cast unit. In order to comply with regulations in many vicinities it is necessary to form the opening or openings I! in the partition II to have an area equal to or preferably greater than the area of the heater flue. This construction is not, of course, in any way a limitation on our invention.

As previously indicated, the number of openings l1 formed in the partition H is not material; there may be one or more than one. In fact, our construction has a substantial amount of the desired effect if the partition H is omitted entirely. Even in the preferred construction, the louvers 20 may be eliminated without impairing the effect of our device to a very substantial degree. While we have described our invention especially in connection with oil and gas fired units, it is obviously not limited thereto, and may be used in substantially any type of heating device.

-While we have described a specific form of our invention for the purpose of illustration and explanation, there are many modifications and alterations which will occur to one skilled in the art and which are entirely within the spirit and scope of our invention, we, therefore, wish to be 7 ing into two compartments one of which incorporates the first and third said openings and the other of which incorporates the second said open ing, said partition being provided with a first opening spaced upwardly from its lower edge and being provided with a second opening spaced upwardly from the first said partition opening by a strip of said partition, 'a generally plane louver secured to said strip of partition extending outwardly only into that compartment, adapted to communicate with a chimney fiue and extending downwardly sufiiciently far to be at least substantially coextensive with. the first said opening in the partition and a generally plane louver extending outwardly from adjacent the partition only into that compartment which is adapted to communicate with a chimney flue and extending downwardly so as to be at least substantially coextensive with the second said opening in the partition.

2. In a draft control a housing having an opening in its top adapted to communicate with a chimney flue, an opening in its bottom, offset from the first said opening, adapted to communicate with thefiue of a heating unit and an opening in its bottom in general registration With the first said opening, a partition dividing said housing into two compartments one of which incorporates the first and third said openings and the other of which incorporates the second said opening, said partition being provided with a plurality of openings and the construction being such that the outside sidewalls of the compartment adapted to communicate with a chimney flue extend downwardly at least substantially as low as the bottom of the lowermost opening in the partition, a strip of partition below each opening therein, and an inclined louver extending outwardly from above each opening in the partition only into that compartment adapted to communicate with a'chimney flue and extending downwardly so as to be at least substantially coextensive with the particular partition opening to which each louver is adjacent.

3. In a draft control a housing having an opening in its top adapted to communicate with a chimney flue, an opening in its bottom, ofiset from the first said opening, adapted to communicate with the flue of a heating unit and an opening in its bottom in general registration with the first said opening, a partition dividing said housing into two compartments one of which incorporates th first and third said openings and the other of which incorporates the second said opening, said partition being provided with a plurality of openings and the construction being such that there is a portion of the partition beneath each opening therein and an inclined louver extending outwardly from above at least one opening in said partition into that compartment adapted to com.- municate with a chimney flue and extending downwardly so as to be in the main coextensive with the particular partition opening to which it is adjacent.

4. In a draft control a housing having an openin in its top adapted to communicate with a chimney flue, an opening in its bottom, off-set from the first said opening, adapted to communicate with the flue of a heating unit and an opening in its bottom in general registrationwithv the first said opening, a partition dividing said housing into two compartments one of which incorporates the first and third said openings and the other'of which incorporates the second said opening, said partition being provided with an opening and the construction being such that the outside side walls of the compartment adapted to communicate with a chimney flue extend downwardly at least substantially as low as the bottom stantially coextensive with the said partition opening.

JOHN L. COBURN. MATTHEW R. COBURN. 

